andykmv
Active member
i have been helping out baz with his galaxy wars PCB (space invaders architecture, not the same layout though as midway or taito) and i have been looking for pics of symptoms as shown on the SI monitor of typical or unusual faults (such as has been done for pacman repair logs/symptoms!)
or related posts see:
- SI typical issues/pics - http://forums.arcade-museum.com/showpost.php?p=1616786&postcount=1
- 8080 CPU signals etc - http://forums.arcade-museum.com/showpost.php?p=1617698&postcount=1
there are no specific schematics or pcb layouts or pinouts for this Artic pcb so i have used the Midway SI L shaped schematic as a starting point and have managed to identify key components in the architecture, their placement on the board so i am annotating the midway schematic with GW layout coords as i go, and annotating the schematic with any obvious diffs as i go.
i thought i had seen a thread with some pics of typical faults but cant for the life of me find the darned thing.
i am trying to compile a list of visible symptoms that i can use as an aid to debuggin baz's board...
the real questions is, can anyone point me to a bunch of SI video screens images showing typical fault symptoms ? or can anyone send me copies of their pics? particularly interested at this stage in pics of issues from Off to the SI bootup before the game attract screen loads
i have an SI multigame board and a good cpu, just need to work my way thru progressively! i think that once we can get it to boot to the attract mode the going will get easier.
repair progress:
firstly we started off with horizontal stripes on screen, with a broken up lines pattern, then the board died leaving only a white screen.
i have since
- desoldered the cpu and installed a socket. cpu is dud. good one installed.
- removed the rams, installed sockets and replaced rams with rams off another clone board.
the pattern i now see on screen is as follows:
from some further probing it looks like ram address A07 is stuck so i need to pull out the DSO and check in more detail and poss replace one of the address counters.
or related posts see:
- SI typical issues/pics - http://forums.arcade-museum.com/showpost.php?p=1616786&postcount=1
- 8080 CPU signals etc - http://forums.arcade-museum.com/showpost.php?p=1617698&postcount=1
there are no specific schematics or pcb layouts or pinouts for this Artic pcb so i have used the Midway SI L shaped schematic as a starting point and have managed to identify key components in the architecture, their placement on the board so i am annotating the midway schematic with GW layout coords as i go, and annotating the schematic with any obvious diffs as i go.
i thought i had seen a thread with some pics of typical faults but cant for the life of me find the darned thing.
i am trying to compile a list of visible symptoms that i can use as an aid to debuggin baz's board...
the real questions is, can anyone point me to a bunch of SI video screens images showing typical fault symptoms ? or can anyone send me copies of their pics? particularly interested at this stage in pics of issues from Off to the SI bootup before the game attract screen loads
i have an SI multigame board and a good cpu, just need to work my way thru progressively! i think that once we can get it to boot to the attract mode the going will get easier.
repair progress:
firstly we started off with horizontal stripes on screen, with a broken up lines pattern, then the board died leaving only a white screen.
i have since
- desoldered the cpu and installed a socket. cpu is dud. good one installed.
- removed the rams, installed sockets and replaced rams with rams off another clone board.
the pattern i now see on screen is as follows:
from some further probing it looks like ram address A07 is stuck so i need to pull out the DSO and check in more detail and poss replace one of the address counters.
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